The present invention relates to an industrial coolant central filtration system, such as those systems utilized to supply an aqueous based, soluble oil coolant to a plurality of separate machining stations to cool the machining stations and to flush machining waste, such as chips, grinding particles, and the like, from the machining station.
Such systems typically include a central filter from which clean, waste-free coolant is supplied by a plurality of high pressure pumps to the machining station; return flumes through which used, waste-bearing coolant returns to the filter for filtration; and flush conduits and nozzles through which coolant is supplied to the flumes at a high transport velocity to move the machining waste through the flumes to the filter.
A typical system of this type is one which circulates about 3,000 gallons per minute of coolant, and one-half or more of the coolant circulation is devoted solely to the flume flushing system. Thus, 1,500 or more gallons per minute are utilized to maintain a flushing transport velocity of between 5 and 10 feet per second merely to prevent the metallic chips and granular particulate from settling in the flumes. Only 1,500 or less gallons per minute of such a system is actually necessary for cooling and flushing the machine tools.
However, the entire flow of 3,000 gallons per minute must be stored, filtered, and continuously recirculated by the multiple pumps, even though relatively light waste loads are generated at the machining stations, particularly where the machining operations are cast iron grinding or honing operations or the like.
In some instances, unfiltered coolant is utilized as the flushing medium, and only filtered coolant is used for flushing the machine tools utilized in the grinding or machining operations. As a result, dual coolant supply header systems are required, as well as separate, constantly operated pumps for the supply of filtered and unfiltered coolant, respectively.
As a result of the prior practices, as above set forth, an unduly large filtration system utilizing multiple pumps in constant operation has been necessary. The large, constant energy requirements of the pumps, the necessary storage and handling facilities for the 3,000 gallons per minute capacity, and the large capital investment necessary, all can be readily appreciated.